Simple Interest
MCQs Math


Question:     What amount does Richard have to pay after 5 years if he takes a loan of $3600 at 6% simple interest?


Correct Answer  $4680

Solution And Explanation

Solution

Given,

Principal (P) = $3600

Rate of Simple Interest (SI) = 6%

Time (t) = 5 years

Thus, Amount (A) = ?

The Rate of Interest is always calculated per annum, i.e. per year.

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% per annum.

Method (1) Using Formula

Calculation of Simple Interest

Formula to Calculate Simple Interest

Simple Interest (SI) = Principal × Rate × Time

Thus, Simple Interest (SI) = $3600 × 6% × 5

= $3600 ×6/100 × 5

= 3600 × 6 × 5/100

= 21600 × 5/100

= 108000/100

= $1080

Thus, Simple Interest = $1080

Calculation of Amount

The total money paid to the lender by a borrower is called the Amount.

In other words, sum of priciple and interest is called the Amount.

Formula to Calculate the Amount

Amount = Principal + Interest

Thus, Amount = $3600 + $1080

= $4680

Thus, Amount to be paid = $4680 Answer

Method (2)

Calculation of Amount when Principal, Rate of Simple Interest and Time are given

Calculation of Amount directly using Principal, SI, and Time

Formula to calculate the Amount

Amount (A) = Principal (P) + Principal(P) × Rate of Interest (SI) × Time (t)

⇒ A = P + PRT

Here in the question, P = $3600

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 5 years

Thus, Amount (A)

= $3600 + ($3600 × 6% × 5)

= $3600 + ($3600 ×6/100 × 5)

= $3600 + (3600 × 6 × 5/100)

= $3600 + (21600 × 5/100)

= $3600 + (108000/100)

= $3600 + $1080 = $4680

Thus, Amount (A) to be paid = $4680 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $3600, the simple interest in 1 year

= 6/100 × 3600

= 6 × 3600/100

= 21600/100 = $216

Thus, simple interest for 1 year = $216

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $216 × 5 = $1080

Thus, Simple Interest (SI) = $1080

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3600 + $1080

= $4680

Thus, Amount to be paid = $4680 Answer


Similar Questions

(1) Daniel took a loan of $6200 at the rate of 9% simple interest per annum. If he paid an amount of $11780 to clear the loan, then find the time period of the loan.

(2) James took a loan of $4000 at the rate of 9% simple interest per annum. If he paid an amount of $6160 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due if John borrowed a sum of $3200 at 5% simple interest for 3 years.

(4) What amount does Charles have to pay after 5 years if he takes a loan of $3900 at 2% simple interest?

(5) If Sandra paid $5340 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(6) Find the amount to be paid if Richard borrowed a sum of $5600 at 10% simple interest for 7 years.

(7) Joseph had to pay $4144 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(8) Robert took a loan of $4200 at the rate of 8% simple interest per annum. If he paid an amount of $7224 to clear the loan, then find the time period of the loan.

(9) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 6% simple interest for 8 years.

(10) What amount will be due after 2 years if David borrowed a sum of $3200 at a 10% simple interest?


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